rescaleNI


Syntax

rescaleNI [options]


Purpose

This program was developed to deal with the increasing size of Monte Carlo needed for PWA. The Monte Carlo is used solely for the purpose of calculating the normalization integrals (NI) and determining the ratio of accepted to generated events. Once a certain number of MC events are used in calculating the NI's there is no advantage to adding additional events. However, to get the needed number of accepted events, often excessive amounts of generated events are needed.

The purpose of rescaleNI is to allow the user to calculate the NI's based on a subset of the MC and then rescale them appropriately. The facility has been built in to do this with both accepted and generated normalization integrals.


Use

rescaleNI will read in a normalization integral file (or series of files) and will apply two possible operations to the file. It will then the file back out to the same name. The files to be operated on are determined by the options given below. In that respect, the program works very similar to int.

There are two operations which can be applied: rescaling and resetting the number of events. Whether these operations are used depends either on the options set or the information in the InfoFile. This file is described below. The rescale function does just that. It multiplies the number of events in the file and each element of the NI by the given factor. Resetting the number of events simply substitutes in the given number for the number of events within the file. It does no operations on the normalization integral. Resetting the number of events occurs after rescaling if both are to be done. This operation is useful if a number of the events generated have an amplitude close to zero and therefore can be initially left out of the calculation.


Options

-f use the enviromental variable $(INFOFILE) for name of file of rescale values. Not implemented as of 1-23-96.
-ffilename use filename for rescale values.
-ia|r a=accepted monte carlo r=raw monte carlo
-l# # = lower edge of mass region
-u# # = upper edge of mass region
-s# # = size of mass bin
-L# # = lower edge of t bin
-U# # = upper edge of t bin
-N# # = actual number of events included in NI. For use without infofile.
-r# # = rescale factor for NI. For use without infofile.
-wfilename use filename for prefix of NI files

InfoFile

The InfoFile is a file which provides rescaleNI with the numbers used to modify the normalization integrals. It is a simple text file which can be created and modified with an editor. Also, facilities for writing an InfoFile are availible in the PWA library. The file has two parts, one for the accepted monte carlo and one for the generated. Each part is started by a blank line and the word Accepted or Generated. The part is ended by a line of 6 zeroes.

Each section contains a series of lines of 6 columns of numbers. Each line represents the numbers for a given mass and t bin. The columns are: Lowmass, Highmass, LowT, HighT, Rescale factor, Number of actual events. A sample InfoFile is given below:

Accepted
1.8 1.9 0.0 2.0 1.177 0.0
1.9 2.0 0.0 2.0 1.188 0.0
2.0 2.1 0.0 2.0 1.172 0.0
2.1 2.2 0.0 2.0 1.170 0.0
0 0 0 0 0 0

Generated
1.8 1.9 0.0 2.0 1.000 357704.0
1.9 2.0 0.0 2.0 1.000 442265.0
2.0 2.1 0.0 2.0 1.905 768922.0
2.1 2.2 0.0 2.0 1.904 915397.0
0 0 0 0 0 0

The bin is defined by the first four numbers. The last two are used to apply operations to the NI file. Whenever a zero appears in the either of the last two columns, that operation is not done. Therefore, in the above example the accepted normalization integrals will be rescaled, but the number of events will not change beyond that rescaling.


Bugs

Currently there is no check on whether an NI file has already been rescaled. Therefore, it is possible to rescale it more than once.

The numbers for the InfoFile need to be generated by the user.


Author

The program and documentation were originally written by Todd Adams. January 23, 1996.